class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        return haystack.find(needle)

if __name__ == '__main__':
    s = Solution()
    h, n = 'hello', 'll'
    h, n = 'hell', ''
    # h, n = 'hello', 'k'
    ret = s.strStr(h, n)
    print(ret)